class_docstr: Reduce learning rate in factor.
  
  Parameters
  ----------
  step: int
      Schedule learning rate after every round.
  factor: float
      Reduce learning rate factor.
docstr: Call to schedule current learning rate.
  
  Parameters
  ----------
  iteration: int
      Current iteration count.
docstr_tok: ["Call","to","schedule","current","learning","rate",".","Parameters","--","--","--","--","--","iteration",":","int","Current","iteration","count","."]
code: def __call__(self, iteration):
      """
      Call to schedule current learning rate.
  
      Parameters
      ----------
      iteration: int
          Current iteration count.
      """
  
      if not self.init:
          self.init = True
          self.old_lr = self.base_lr
      lr = self.base_lr * math.pow(
          self.factor, int(iteration / self.step)
      )
      if lr != self.old_lr:
          self.old_lr = lr
          logging.info(
              "At Iteration [%d]: Swith to new learning rate %.5f",
              iteration,
              lr,
          )
      return lr
  
file_path: mxnet/python/mxnet/misc.py
imports: import math
  import logging
label_desc: Use image node_id 2 for calling the FactorScheduler obj's underlying member method code with example usage: obj.__call__(iteration) and returns: lr